[PATCH v3 4/4] ASoC: fsl_asrc_dma: allocate memory from dma device

Shengjiu Wang
2026-02-03T03:13:48Z

The dma-coherent property is used to indicate a device is capable of
coherent DMA operations. On i.MX952, one of EDMA devices support such
feature, in order to support the EDMA device, the memory needs to be
allocated from the DMA device.

The code change here is to make this driver compatible for non
dma-coherent and dma-coherent dma devices.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
sound/soc/fsl/fsl_asrc_dma.c | 48 ++++++++++++++++++++++++++++++------
1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index 7dacc06b2f02..348b0aabfa68 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -449,18 +449,52 @@ fsl_asrc_dma_pcm_pointer(struct snd_soc_component *component,
static int fsl_asrc_dma_pcm_new(struct snd_soc_component *component,
struct snd_soc_pcm_runtime *rtd)
{
- struct snd_card *card = rtd->card->snd_card;
+ struct device *dev = component->dev;
+ struct fsl_asrc *asrc = dev_get_drvdata(dev);
+ struct fsl_asrc_pair *pair;
struct snd_pcm *pcm = rtd->pcm;
+ struct dma_chan *chan;
int ret;

- ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
- if (ret) {
- dev_err(card->dev, "failed to set DMA mask\n");
- return ret;
+ pair = kzalloc(size_add(sizeof(*pair), asrc->pair_priv_size), GFP_KERNEL);
+ if (!pair)
+ return -ENOMEM;
+
+ pair->asrc = asrc;
+ pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);
+
+ /* Request a pair, which will be released later.
+ * Request pair function needs channel num as input, for this
+ * pair, we just request "1" channel temporarily.
+ */
+ ret = asrc->request_pair(1, pair);
+ if (ret < 0) {
+ dev_err(dev, "failed to request asrc pair\n");
+ goto req_pair_err;
+ }
+
+ /* Request a dma channel, which will be released later. */
+ chan = asrc->get_dma_channel(pair, IN);
+ if (!chan) {
+ dev_err(dev, "failed to get dma channel\n");
+ ret = -EINVAL;
+ goto dma_chan_err;
}

- return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
- card->dev, FSL_ASRC_DMABUF_SIZE);
+ ret = snd_pcm_set_fixed_buffer_all(pcm,
+ SNDRV_DMA_TYPE_DEV,
+ chan->device->dev,
+ FSL_ASRC_DMABUF_SIZE);
+
+ dma_release_channel(chan);
+
+dma_chan_err:
+ asrc->release_pair(pair);
+
+req_pair_err:
+ kfree(pair);
+
+ return ret;
}

struct snd_soc_component_driver fsl_asrc_component = {
--
2.34.1